1. Field of the Invention
The present invention relates to a lens-fitted photo film unit, flash device and lens-fitted photo film system. More particularly, the present invention relates to a lens-fitted photo film unit of which a flash device can be used repeatedly by connection with a new lens-fitted photo film unit after using the initial lens-fitted photo film unit, and a flash device, and a lens-fitted photo film system.
2. Description Related to the Prior Art
A lens-fitted photo film unit is known as a single-use camera pre-loaded with photo film. The lens-fitted photo film unit includes a main body, and front and rear covers. The main body contains photo film, and has a mechanism for taking an exposure. The front and rear covers cover the front and rear of the main body. Those relevant parts are formed from plastic material.
The lens-fitted photo film unit has typical features of a small size, a simple structure, a low cost and the like. However, there are additional structures provided in the lens-fitted photo film unit for various purposes, for example, a flash type of the lens-fitted photo film unit. The flash type has a flash device, which includes a flash emitter and a flash circuit board supplied with power by a battery.
After a user exposes all the frames on the photo film, he or she forwards a used lens-fitted photo film unit to a photo finisher or photo laboratory without disassembly, and requests printing. When photographic prints are obtained, the developed photo film is also returned to the user. A housing of the used lens-fitted photo film unit, in contrast, is collected, handled by a photo finisher, and withdrawn to a camera manufacturer.
There are suggestion of the camera manufacturer for recycling the used lens-fitted photo film unit in view of preventing environmental pollution and utilizing resources. A circulation type of manufacturing system has been created by designing numerous processes including a design of a product and a manufacturing line specifically in consideration of the recycling.
The camera manufacturer disassembles the used lens-fitted photo film unit. The flash device and exposure unit are cleaned, inspected and then reused. Plastic parts are melted and pelletized, and regenerated as plastic material. The lens-fitted photo film unit is originally constructed for a single use. To keep its cost low, durability of parts of the lens-fitted photo film unit is considerably low in comparison with parts used in a widely used camera. For the flash device and other parts to be reused, quality is maintained by suitable inspection and repair if desired.
The recycling is also effective in lowering a market price of the lens-fitted photo film unit. Among the various parts of the lens-fitted photo film unit, the flash device is remarkably expensive. The reuse of the flash device is highly advantageous for the purpose of lowering the cost of the lens-fitted photo film unit.
However, withdrawal of products of the used lens-fitted photo film unit to the camera manufacturer is not complete. There is a distribution of part of all the products of the used lens-fitted photo film unit to third parties, such as photo film reloading dealers, part-reusing dealers and the like. The reloading dealers load the used lens-fitted photo film unit with unexposed photo film. The part-reusing dealers utilize the used lens-fitted photo film unit, obtains parts constituting the main body, and assembles the lens-fitted photo film unit as a newly created product. The reloaded products and part-reused products are packaged, and marketed as unused products. A price of those is very inexpensive, because the flash device in the reloaded products or part-reused products is originally obtained without a costly process.
However, the reloaded products or the part-reused products are likely to have great problems in the quality because the parts are not cleaned, repaired or inspected suitably. Such problems may cause damages to reputation of the lens-fitted photo film unit with good performance, and also reputation of the camera manufacturer of the lens-fitted photo film unit.
In the case of the unsuitable reuse of parts, only limited parts, such as flash device, are reused for the reason of high cost and great ease in operation for the reuse. Remaining parts other than the flash device or the like are likely to be discarded in spite of much possibility of reuse. If the unsuitable reuse of parts is continued on a large scale, there is no achievement of purposes of the circulation type of the manufacturing system established by the camera manufacturer, the purposes being for prevention of environmental pollution, effective utilization of resources, and the like. Furthermore, advantages of a low cost caused by the reuse cannot be obtained. It may cause failure and destruction of the circulation type of the manufacturing system.
JP-A 7-120883 discloses examples of preventing unsuitable reloading of photo film on the side of the camera manufacturer. Some of the examples has been worked and used. However, there is no known technique of preventing unsuitable reuse of flash device and other relevant parts of the used lens-fitted photo film unit.